Struct tarantool_module::index::Index

pub struct Index { /* fields omitted */ }

An index is a group of key values and pointers.

Implementations

impl Index

pub fn get<K>(&self, key: &K) -> Result<Option<Tuple>, Error> where
    K: AsTuple, 

Get a tuple from index by the key.

Please note that this function works much more faster than select

• key - encoded key in MsgPack Array format ([part1, part2, ...]).

Returns a tuple or None if index is empty

pub fn select<K>(
    &self,
    iterator_type: IteratorType,
    key: &K
) -> Result<IndexIterator, Error> where
    K: AsTuple, 

Allocate and initialize iterator for index.

This is an alternative to space.select() which goes via a particular index and can make use of additional parameter that specify the iterator type.

• type - iterator type
• key - encoded key in MsgPack Array format ([part1, part2, ...]).

pub fn delete<K>(&mut self, key: &K) -> Result<Option<Tuple>, Error> where
    K: AsTuple, 

Delete a tuple identified by a key.

Same as space.delete(), but key is searched in this index instead of in the primary-key index. This index ought to be unique.

• key - encoded key in MsgPack Array format ([part1, part2, ...]).

Returns the deleted tuple

pub fn update<K, Op>(
    &mut self,
    key: &K,
    ops: &Vec<Op>
) -> Result<Option<Tuple>, Error> where
    K: AsTuple,
    Op: AsTuple, 

Update a tuple.

Same as space.update(), but key is searched in this index instead of primary key. This index ought to be unique.

• key - encoded key in MsgPack Array format ([part1, part2, ...]).
• ops - encoded operations in MsgPack array format, e.g. [['=', field_id, value], ['!', 2, 'xxx']]

Returns a new tuple.

See also: index.upsert()

pub fn upsert<T, Op>(
    &mut self,
    value: &T,
    ops: &Vec<Op>
) -> Result<Option<Tuple>, Error> where
    T: AsTuple,
    Op: AsTuple, 

Execute an UPSERT request.

Will try to insert tuple. Update if already exists.

• value - encoded tuple in MsgPack Array format ([field1, field2, ...])
• ops - encoded operations in MsgPack array format, e.g. [['=', field_id, value], ['!', 2, 'xxx']]

Returns a new tuple.

See also: index.update()

pub fn len(&self) -> Result<usize, Error>

Return the number of elements in the index.

pub fn bsize(&self) -> Result<usize, Error>

Return the number of bytes used in memory by the index.

pub fn random(&self, seed: u32) -> Result<Option<Tuple>, Error>

Return a random tuple from the index (useful for statistical analysis).

• rnd - random seed

pub fn min<K>(&self, key: &K) -> Result<Option<Tuple>, Error> where
    K: AsTuple, 

Return a first (minimal) tuple matched the provided key.

• key - encoded key in MsgPack Array format ([part1, part2, ...]).

Returns a tuple or None if index is empty

pub fn max<K>(&self, key: &K) -> Result<Option<Tuple>, Error> where
    K: AsTuple, 

Return a last (maximal) tuple matched the provided key.

• key - encoded key in MsgPack Array format ([part1, part2, ...]).

Returns a tuple or None if index is empty

pub fn count<K>(
    &self,
    iterator_type: IteratorType,
    key: &K
) -> Result<usize, Error> where
    K: AsTuple, 

Count the number of tuple matched the provided key.

• type - iterator type
• key - encoded key in MsgPack Array format ([part1, part2, ...]).

pub fn extract_key(&self, tuple: Tuple) -> Tuple

Extract key from tuple according to key definition of given index. Returned buffer is allocated on box_txn_alloc() with this key.

• tuple - tuple from which need to extract key.